The purpose of the proposed research is to identify and investigate biochemical processes involved in the formation and maintenance of retinal adhesion. Cell surface glycoproteins have been implicated in several cell recognition processes which accompany embryonic tissue adhesion and differentiation. Therefore, one approach is to examine the development of glycoprotein production in the embryonic chick eye, by means of labelled precursors and assays of relevant enzymes (for example, L-glutamine-D-fructose-6-phosphate aminotransferase). The role of glucocorticoid hormones will be investigated. An inquiry into the role of proteins, glycoproteins, and glycosaminoglycans in retinal adhesion in the adult eye has been initiated by examination of these molecules in the interphotoreceptor matrix of the bovine eye. These species are being fractionated and characterized by gel electrophoresis and chromatography (affinity and gel filtration). Their effect upon retinal adhesion is being measured in a cell aggregation assay with pigment epithelial cells and rod outer segments. Cell plasma membranes will be examined for adhesive and physicochemical interactions. Proteins involved in other processes of interest in the interphotoreceptor matrix, such as retinoid binding proteins and hydrolytic enzymes, will be investigated. The long-range objective is to apply the results to the prevention and treatment of retinal detachment.